What is airtightness?
Airtightness is about eliminating all unintended gaps and cracks, holes, splits and tears where air can move into and out of the ‘conditioned’ space (heated or cooled space) of the building.
Such gaps, cracks etc can account for up to 50pc of all heat losses through the external envelope of a building, and can be caused by poor build design, poor workmanship or the use of wrong or inappropriate materials. It is important to remember that an airtight building does not mean it is completely sealed, rather it means that unintended air leakage has been reduced to a minimum
Why airtightness is so important in construction?
Airtightness is important for avoiding heat loss as it means less uncontrolled air movement in and out of the building. Less heat loss also means your heating system will work more efficiently, thereby reducing heating bills and energy wastage. It also contributes to maintaining thermal comfort (ie. insulating better in winter and reducing overheating in the summer).
It can improve health by preventing substances that can provoke allergies being carried into the building via air leakage and can also result in better sound insulation within the home.
Building durability is also enhanced through airtightness by preventing damage caused by moisture-laden cold air leaking into the building envelope and condensing.
In conjunction with a properly designed ventilation system, airtightness will eliminate damp and mould growth in the building fabric and vastly improve indoor air quality.
And last but not least, achieving good airtightness necessitates a higher focus on build quality and quality workmanship, which in turn should mean fewer call backs.